[PATCH bpf-next 1/7] perf/core: add perf_get_event() to return perf_event given a struct file

Yonghong Song
2018-05-15T23:45:27Z

A new extern function, perf_get_event(), is added to return a perf event
given a struct file. This function will be used in later patches.

Signed-off-by: Yonghong Song <yhs@fb.com>
---
include/linux/perf_event.h | 5 +++++
kernel/events/core.c | 8 ++++++++
2 files changed, 13 insertions(+)

diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index e71e99e..b5c1ad3 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -868,6 +868,7 @@ extern void perf_event_exit_task(struct task_struct *child);
extern void perf_event_free_task(struct task_struct *task);
extern void perf_event_delayed_put(struct task_struct *task);
extern struct file *perf_event_get(unsigned int fd);
+extern struct perf_event *perf_get_event(struct file *file);
extern const struct perf_event_attr *perf_event_attrs(struct perf_event *event);
extern void perf_event_print_debug(void);
extern void perf_pmu_disable(struct pmu *pmu);
@@ -1289,6 +1290,10 @@ static inline void perf_event_exit_task(struct task_struct *child) { }
static inline void perf_event_free_task(struct task_struct *task) { }
static inline void perf_event_delayed_put(struct task_struct *task) { }
static inline struct file *perf_event_get(unsigned int fd) { return ERR_PTR(-EINVAL); }
+static inline struct perf_event *perf_get_event(struct file *file)
+{
+ return ERR_PTR(-EINVAL);
+}
static inline const struct perf_event_attr *perf_event_attrs(struct perf_event *event)
{
return ERR_PTR(-EINVAL);
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 67612ce..1e3cddb 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -11212,6 +11212,14 @@ struct file *perf_event_get(unsigned int fd)
return file;
}

+struct perf_event *perf_get_event(struct file *file)
+{
+ if (file->f_op != &perf_fops)
+ return ERR_PTR(-EINVAL);
+
+ return file->private_data;
+}
+
const struct perf_event_attr *perf_event_attrs(struct perf_event *event)
{
if (!event)
--
2.9.5